Current Topic: Health promotion and behavior change
Week 5
Hoorcollege 2.1: evolution and development of health behavior
Learning objectives:
After this lecture, you’re able to:
● Explain why humans get depressed
● Explain the mismatch hypothesis of depression
● Explain health behavior from a functional and evolutionary perspective
● Apply hunter-gatherer knowledge to modern health issues
learning goal: Why do people get depressed, what is the function of depression, what is the
evolutionary background
Why do humans get depressed
*What is depression?
Depression in humans:
- feelings of sadness/emptiness
- no interest or pleasure in activities
- weight changes
- insomnia of hypersomnia
- agitation or retardation
- fatigue or loss of energie
- feeling of worthlessness
- poor concentration
- recurrent thoughts of death
-
*evolution and depression - why study it?
- depression is common
- high heritability (erfelijkheid)
, - people with depression get less children
- paradox: why did natural selection not eliminate depression from the population?
- review keller & miller, behave brain sciences
Prevalence of depression
- lifetime prevalence (USA) 19,2%
- lifetime prevalence (NL) 17.9%
- University students 30,6%
- persistent depressive disorder (USA) 4,7%
Conclusion: modern humans behave like captive apes
Solution
Do we all need to become hunters and gatherers again? (answered later on)
Heritability of depression
- heritability = 37%
- genome-wide association study: No SNPS achieved significance
What is the function of depression?
Why do humans get depressed
- cry for help
- reaction to losses
- seasonal - no activity in winter
- energy conservation
- rumination - solving problems
- association with inflammation/infections
- mismatch
,Unified model of depression
Mismatch hypothesis
We are not adapted to modern environments but to ancestral environments, this result is a
mismatch
Environment of evolutionary adaptedness
- savannah-like environment
- hunter-gatherer society
- nomadic lifestyle
- physical dangers
- high infant mortality
- food scarcity
, Hadza: food
- tubers
- berries
- meat
- baobab
- honey
Mismatch hypothesis: changes in:
- diet
- physical activity
- childrearing
- sunlight
- sleep
- social interactions
*Does depression result from a mismatch? How to test this hypothesis?
example 1:
- developing countries → less mismatch
- rich countries → more mismatch
- results:
Example 2:
- rural areas → less mismatch
- urban areas → more mismatch
- results urbanization
- high prevalence of diagnoses in stockholm, sweden, compared to swedish
rural areas:
- depression, anxiety, diabetes, hypertension, asthma
- review urbanization
- association between urbanization and depression, but many
confounding variables for example:
- poverty
Week 5
Hoorcollege 2.1: evolution and development of health behavior
Learning objectives:
After this lecture, you’re able to:
● Explain why humans get depressed
● Explain the mismatch hypothesis of depression
● Explain health behavior from a functional and evolutionary perspective
● Apply hunter-gatherer knowledge to modern health issues
learning goal: Why do people get depressed, what is the function of depression, what is the
evolutionary background
Why do humans get depressed
*What is depression?
Depression in humans:
- feelings of sadness/emptiness
- no interest or pleasure in activities
- weight changes
- insomnia of hypersomnia
- agitation or retardation
- fatigue or loss of energie
- feeling of worthlessness
- poor concentration
- recurrent thoughts of death
-
*evolution and depression - why study it?
- depression is common
- high heritability (erfelijkheid)
, - people with depression get less children
- paradox: why did natural selection not eliminate depression from the population?
- review keller & miller, behave brain sciences
Prevalence of depression
- lifetime prevalence (USA) 19,2%
- lifetime prevalence (NL) 17.9%
- University students 30,6%
- persistent depressive disorder (USA) 4,7%
Conclusion: modern humans behave like captive apes
Solution
Do we all need to become hunters and gatherers again? (answered later on)
Heritability of depression
- heritability = 37%
- genome-wide association study: No SNPS achieved significance
What is the function of depression?
Why do humans get depressed
- cry for help
- reaction to losses
- seasonal - no activity in winter
- energy conservation
- rumination - solving problems
- association with inflammation/infections
- mismatch
,Unified model of depression
Mismatch hypothesis
We are not adapted to modern environments but to ancestral environments, this result is a
mismatch
Environment of evolutionary adaptedness
- savannah-like environment
- hunter-gatherer society
- nomadic lifestyle
- physical dangers
- high infant mortality
- food scarcity
, Hadza: food
- tubers
- berries
- meat
- baobab
- honey
Mismatch hypothesis: changes in:
- diet
- physical activity
- childrearing
- sunlight
- sleep
- social interactions
*Does depression result from a mismatch? How to test this hypothesis?
example 1:
- developing countries → less mismatch
- rich countries → more mismatch
- results:
Example 2:
- rural areas → less mismatch
- urban areas → more mismatch
- results urbanization
- high prevalence of diagnoses in stockholm, sweden, compared to swedish
rural areas:
- depression, anxiety, diabetes, hypertension, asthma
- review urbanization
- association between urbanization and depression, but many
confounding variables for example:
- poverty
